What do dol­phins do dur­ing storms?

BBC Wildlife Magazine - - Q&a - Jon Dunn

We’re not en­tirely sure. Study­ing marine mam­mals at sea is tricky at the best of times, let alone dur­ing bad weather.

It has been sug­gested that coastal dol­phins can sense changes in at­mo­spheric pres­sure, head­ing for deeper, less tur­bu­lent waters be­fore the bad weather hits. Cetaceans ex­hale ex­plo­sively and then in­hale again very quickly, re­quir­ing them to spend rel­a­tively lit­tle time at the sur­face. Nev­er­the­less, head­ing for the deep is prob­a­bly wise, as very strong storms can have dev­as­tat­ing ef­fects – one bot­tlenose pop­u­la­tion in the Gulf of Mex­ico de­creased by a third af­ter Hur­ri­cane Ka­t­rina in 2005.

We’re only just be­gin­ning to un­der­stand how th­ese mam­mals re­cu­per­ate in the af­ter­math of such weather events. One study showed that dol­phins can re­struc­ture their so­cial groups, re­plac­ing lost mem­bers with new ones en­ter­ing the com­mu­nity. Another noted de­creased lev­els of ag­gres­sion be­tween bot­tlenose and At­lantic spot­ted dol­phins, the males of which fight to es­tab­lish dom­i­nance. Long-term im­pli­ca­tions are still un­known.

When bad weather hits, dol­phins (here the com­mon va­ri­ety) lay low.

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